In fabrications, especially those made of sheet metal, it is often desirable to provide a finished product in which the welds or joints which interconnect a number of pieces are hidden so that the entire product appears as a single uniform piece with smooth, uninterrupted lines. To accomplish this the welds or joints may be disposed in a recess or trench which is subsequently filled with a filler, such as lead if the fabrication is of steel, which is then ground down to match the flow of the surfaces surrounding the weld trench. Lead is the preferred filler for steel sheet fabrications because it adheres well to steel and similar metals and is easy to work. The lead or other filler is smoothed to the proper contour, usually by grinding with a motor-driven grinder operated by a man. A number of shortcomings occur from this approach. Information indicates that lead dust, vapors and particles are a health hazard and could be dangerous to grinder operators. As a result extreme caution surrounds the grinding of such lead fillers, including double locker rooms, clean suits, showers and other extreme, time-consuming, expensive measures.